what is a pan evac? Paul had recomended a cam for this but i can't think of it right now but, it was a comp cam. so i might just ask for it....i'm really not trying to go too hot because i won't be racing it. do you have a grid or cam choice in mind.. something that i don't need a stall converter for???

 

Pressure builds up inside of your engine when it's running and the crankshaft has to push through that extra pressure, which of course causes a loss in power. Almost like running another high load accessory on the pulley system. Your Stock PCV system kind of helps remove that pressure via vacuum into the intake manifold. There's a couple problems with the stock system. It not that efficient and it does NOT work at all at WOT since there's not really any vacuum. It also injects hot oily gases into your intake air charge.

Then there's running open breathers on both sides that allow pressure to simply escape through diffusion. Not really that effective either, and you have a good chance of oil coming out onto your engine slowly and causing a mess. Unless you run catch cans.

A Pan-evan or 'Header crankcase evacuation system' is where you use the exhaust to pull the gases out of the crankcase via the valve covers. You put some one-way check valves on your valve covers, holes to the front, and put some nipples in your collector; then run hose to connect them. The exhaust flow will cause vacuum to pull the gases out of the crankcase, and not only will you remove the pressure you'll actually have negative pressure (vacuum) inside of the crankcase. Therefore the crankshaft and pistons don't have to fight all that pressure AND you won't have seals blowing and oil leaking out random spots with gaskets. It's FREE POWER and keeps your engine cleaner.





Who doesn't want 20-50 free ponies??? You can pick up the check valves and exhaust nipples from summit for like $55.

Don't run with Cats though, there will be some oil residue escape that you don't want building up in a ceramic honey comb. Can't really run this if you have emissions to pass.

 

As far as Cam, I'm not going to recommend one because I'm not a cam guy. Neither me or anyone else I've seen on this site actually understand cam events. Through trial and error guys can recommend cams that work good enough with your set-up. But your set-up is custom, why not pay an extra $100 or so to get a customs grind specifically for your application?

Just cause your doing a mild build and not racing doesn't mean you couldn't highly benefit from a custom cam. If your just upgrading to upgrade and not because your current engine is broke, why not do it right the first time? You'll just end up paying even more to do it twice.

Here's an example from a guy over on sbftech.com with similar cubes.

347--190FAC heads, Victor Jr. intake, Hydraulic roller cam, Holley 750DP.

475HP @ 5900rpms, 441lb/ft @ 5300rpms.

Most are gonna say, No torque down low right? Guess what, it's making 387lb/ft of torque at 3000rpms! It is NOT gonna get much lower than that under 3000.



You know why it makes that type of low-end torque and all that upper end? Proper valve events (CAMSHAFT). When you have the proper valve events, you'll make more power EVERYWHERE.

There's also Jay Allen's 347 with touched up 190FAC heads (not ported), Ported Vic Jr., 4500 Dominator carb, 2" primary headers.... 2HP/Cu-in, 694 @ 7500rpms, 511tq @ 5600 through 6300... AND it still made 411lb/ft at 3000rpms and stayed above 400lb/ft until over 8400rpms. I'll get you the dyno sheets if you want to see them.

Provided you don't need that much acceleration and top-end, the point I'm trying to make is big heads/intake/exhaust losing low-end power and only for cars or racing applications is all crap. That came from people just throwing in random cams without knowing anything about valve events, cams have to be more exact with better parts. With the proper cam, you will make more power everywhere. You should be able to easily make over 400lb/ft and HP with TFS TW 170FAC heads, which are only $1200.

 

well for my daily needs i think that the combo that i'm looking at will be just fine but i do thank you for all of those inputs. i'm gonna print this out and keep it in my repair manual just in case i want to do some extra work later on. i'll also be going to the local pull a part to see what goodies i can find.